/* Copyright (C) 2004 - 2006  db4objects Inc.  http://www.db4o.com

This file is part of the db4o open source object database.

db4o is free software; you can redistribute it and/or modify it under
the terms of version 2 of the GNU General Public License as published
by the Free Software Foundation and as clarified by db4objects' GPL 
interpretation policy, available at
http://www.db4o.com/about/company/legalpolicies/gplinterpretation/
Alternatively you can write to db4objects, Inc., 1900 S Norfolk Street,
Suite 350, San Mateo, CA 94403, USA.

db4o is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
59 Temple Place - Suite 330, Boston, MA  02111-1307, USA. */
namespace Db4objects.Db4o.Internal.Query.Processor
{
	/// <exclude></exclude>
	public abstract class QEStringCmp : Db4objects.Db4o.Internal.Query.Processor.QEAbstract
	{
		public bool caseSensitive;

		public QEStringCmp(bool caseSensitive_)
		{
			caseSensitive = caseSensitive_;
		}

		internal override bool Evaluate(Db4objects.Db4o.Internal.Query.Processor.QConObject
			 a_constraint, Db4objects.Db4o.Internal.Query.Processor.QCandidate a_candidate, 
			object a_value)
		{
			if (a_value != null)
			{
				if (a_value is Db4objects.Db4o.Internal.Buffer)
				{
					a_value = a_candidate._marshallerFamily._string.ReadFromOwnSlot(a_constraint.i_trans
						.Stream(), ((Db4objects.Db4o.Internal.Buffer)a_value));
				}
				string candidate = a_value.ToString();
				string constraint = a_constraint.i_object.ToString();
				if (!caseSensitive)
				{
					candidate = candidate.ToLower();
					constraint = constraint.ToLower();
				}
				return CompareStrings(candidate, constraint);
			}
			return a_constraint.i_object == null;
		}

		public override bool SupportsIndex()
		{
			return false;
		}

		protected abstract bool CompareStrings(string candidate, string constraint);
	}
}
